The present invention relates to a support structure for clamping onto a body in a radial direction and more particularly, although not exclusively, to a support structure than can hold a body at a plurality of locations on an internal or external surface of the body spaced about a central axis.
There exist a number of applications in which it is necessary to support or clamp a body, such as a machine component or assembly, securely about its periphery. This need exists particularly in the manufacture, inspection, transportation, maintenance and repair/overhaul of rotating machinery in which generally cylindrical or annular components/assemblies are commonplace. Support structures are often required to hold such components in a predetermined orientation such that one or more operations can be performed on the component whilst held fast. Depending on the operation in question, access to the interior and/or exterior of component may be required whilst held.
One example of a support arrangement of this type is a clamping ring shown in FIG. 1, in which a deformable collar in the form of a metal band is placed around an object and a screw thread is used to cause the collar to contract, thereby gripping the exterior of the object about its periphery. Hose clamps provide a conventional form of such supports.
Although cheap and compact, there are a number of problems with such clamping systems. Hose-style clamping is best suited to the external clamping of small diameters, but it offers no facility to internally clamp an annular body. Such clamps are also restricted to exerting relatively low clamping forces, due to the need for a deformable, and therefore thin, metal band, which must be flexible enough to conform to an annular loop of the required diameter. Since the thin metal loop will conform to the component, there is no guarantee that the clamp is maintaining a truly circular shape, thereby meaning that circularity can be a problem, particularly when supporting thin-walled components and/or when tolerances are particularly tight.
Another example of a tool for clamping cylindrical objects is a hinged pipe clamp (as shown in FIG. 2 or a slotted shaft collar as shown in FIG. 3. These clamps have a centre aperture that is slightly larger the object to be held. A portion of the circumference removed to provide a gap between the opposing ends of the collar and a bolt is used to reduce the size of the gap and thereby clamp the collar onto the body within the central aperture. This type of clamp can only clamp onto an external surface of the body and can only accommodate bodies within a very narrow band of deviation.
Conventional collar clamps are also prone to clamping at opposing discrete pinch points, e.g. at two points perpendicular to the clamping screw, rather than evenly about the entire periphery of the body. This can cause significant point loading of the clamping force which causes unwanted stress, and potentially deformation, in the clamped body.
Whilst a number of variations on the above clamp types have been developed for specific applications or components, the above problems generally persist and thus any single clamp is typically tailored to accommodate bodies which display only a very small degree of deviation from a nominal profile.
It is an aim of the present invention to provide a support structure that can mitigate or overcome one or more of the above-identified problems. It may be considered an aim of the invention to provide a support that provides more uniform and/or adaptable clamping of a body, for example whilst allowing access to the clamped body.